1. Field of the Invention
The invention relates to a semiconductor device and a circuit formed by the semiconductor device, and more particularly, to an electrostatic discharge protection structure and an electrostatic discharge protection circuit.
2. Description of Related Art
Electrostatic discharge (ESD) is an effect in which an electric charge moves rapidly (discharge) in a short period of time through a discharge path after accumulating on a non-conductor or an ungrounded conductor. Electrostatic discharge damages the circuit formed by the components of an integrated circuit. For instance, the human body, machines used to package integrated circuits, and instruments for testing integrated circuits are all common charged bodies, and when a charged body comes in contact with a chip, the charged body may discharge to the chip. The instantaneous power of the electrostatic discharge may cause damage or failure to the integrated circuit in the chip.
The known electrostatic discharge protection apparatus is commonly built with an electrostatic discharge clamp (ESD clamp). Alternately, a silicon controlled rectifier (SCR) is used to build the electrostatic discharge protection apparatus without the use of an ESD clamp. Currently, issues faced by the SCR technology include the triggering voltage (Vt) being too high and the holding voltage (Vh) being too low. A triggering voltage (Vt) that is too high is more difficult to be triggered by the SCR, often causing the components in the circuit to become damaged before the SCR is triggered. A holding voltage that is too low causes the SCR to activate from being readily affected by noise during operation, leading to a latch-up effect after being triggered.